The objective of the proposed research is to study the extent of binocular vision in subjects with strabismus, including the anomalous binocular vision in subjects who have developed anomalous retinal correspondence. Binocularity will be studied psychophysically by means of the interocular transfer of the motion aftereffect using moving gratings varying in size, spatial frequency, and orientation. This sensory testing along with detailed clinical evaluation is expected to lead to an understanding of binocularity and the sensory mechanisms which contribute to the maintenance of ocular alignment.